Svirsky ran a series of tests where he had participants fill out
online surveys for money and made them decide whether to share
their Facebook profile data with a survey taker in exchange for a
bonus (in some cases, 50 cents). In a direct trade-off scenario,
Svirsky found that 64 percent of participants refused to share
their Facebook profile in exchange for 50 cents and a majority
were “unwilling to share their Facebook data for $2.50.” In sum:
Respondents generally sacrificed a small bonus to keep from
turning over personal information.

But things changed when Svirsky introduced the smallest bit of
friction. When participants were faced with what he calls “a
veiled trade-off,” where survey takers had to click to learn
whether taking the survey without connecting to Facebook would be
free or cost them 50 cents, only 40 percent ended up refusing to
share their data.

Friction is largely underrated in user experience design. Some of the people who understand friction’s effect best, alas, are those purposely designing privacy controls to make them even just a bit harder to use, understand, or discover.

The lack of friction in the Sign In With Apple experience — especially using a device with Face ID or Touch ID — is a key part of why I expect it to be successful. It’s not just more private than signing in with Google or Facebook, it’s as good or better in terms of how few steps it takes.

Designers need to design for what people will do, not what people should, in theory, do.